I am expecting 6 maybe 7 of original cast In future.I don't expect any major new characters In future.Cameos by a couple new characters Is possable.

It's also going to depend how DOFP Is structed and who the time traveler Is.

If the future Is just 20-25 minutes at beging of film with Wolverine or Rogue/Kitty(depending which one they would Include In film) It defently won't have any new characters.If film goes back and forth between future and 1960's and the time travel Is Xavier switching minds with younger self then you have more opportunity for cameos.

It seems likely we will get familiar faces in the future, yes.

In the comics and cartoons, the key characters like Storm, Cyclops, Iceman, etc were in the past setting, so we didn't need them in the future.

But in the film, we don't have Storm, Cyclops, Iceman, Rogue in the 60s, so if they are going to appear anywhere, it seems likely to be the future.

It all depends on what story they have chosen, which time periods it is set in, if it's an alternate future or not. Until we know all that, it's impossible to be certain who might appear.

They might well decide to bring younger versions of Storm, Cyclops and Jean into the 60s and ignore the fact that the timeline would mean those three aren't born yet.

For instance, Havok, Banshee and Beast could get captured and Xavier has to find a new team to rescue them, similar to what happened in Giant Size X-Men story Second Genesis in 1975. In that story, the original team (Cyclops, Jean, Iceman, Angel, Beast, Havok, Polaris) were captured by the mutant living island Krakoa and Xavier recruited Storm, Colossus, Banshee, Nightcrawler, Thunderbird, Sunfire and Wolverine to stop them. (Of course, the later retcon Deadly Genesis had him first recruiting another new team, who all failed in the rescue mission - Darwin, Petra, Sway, Vulcan).